Electronic device

ABSTRACT

This technology provides an electronic device. An electronic device in accordance with an implementation of this document may include a semiconductor memory, and the semiconductor memory may include: an under layer including a plurality of material layers having a different crystal structures; a first magnetic layer formed over the under layer and having a variable magnetization direction; a tunnel barrier layer formed over the first magnetic layer; and a second magnetic layer formed over the tunnel barrier layer and having a pinned magnetization direction.

CROSS-REFERENCE TO RELATED APPLICATION

This patent document claims priority of Korean Patent Application No.10-2015-0168318, entitled “ELECTRONIC DEVICE” and filed on Nov. 30,2015, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This patent document relates to memory circuits or devices and theirapplications in electronic devices or systems.

BACKGROUND

Recently, as electronic devices or appliances trend towardminiaturization, low power consumption, high performance,multi-functionality, and so on, there is a demand for electronic devicescapable of storing information in various electronic devices orappliances such as a computer, a portable communication device, and soon, and research and development for such electronic devices have beenconducted. Examples of such electronic devices include electronicdevices which can store data using a characteristic switched betweendifferent resistant states according to an applied voltage or current,and can be implemented in various configurations, for example, an RRAM(resistive random access memory), a PRAM (phase change random accessmemory), an FRAM (ferroelectric random access memory), an MRAM (magneticrandom access memory), an E-fuse, etc.

SUMMARY

The disclosed technology in this patent document includes memorycircuits or devices and their applications in electronic devices orsystems and various implementations of an electronic device, in which anelectronic device includes a semiconductor memory which can improvecharacteristics of a variable resistance element.

In an implementation, an electronic device may include a semiconductormemory, and the semiconductor memory may include an under layerincluding a plurality of material layers having a different crystalstructures; a first magnetic layer formed over the under layer andhaving a variable magnetization direction; a tunnel barrier layer formedover the first magnetic layer; and a second magnetic layer formed overthe tunnel barrier layer and having a pinned magnetization direction.

The under layer may include a first material layer; a second materiallayer; and a third material layer which have different crystalstructures from each other, wherein the third material layer may includea dusting layer. The under layer may have a multi-stack structure inwhich the first material layer, the second material layer and the thirdmaterial layer are sequentially stacked. The third material layer may beformed as thinly as possible within a predetermined range. The underlayer may have a multi-stack structure in which the first materiallayer, the third material layer and the second material layer aresequentially stacked. The third material layer may be formed as thicklyas possible within a predetermined range. The under layer may include afirst material layer has an FCC (Face Centered Cubic) crystal structure,a second material layer has a NaCl crystal structure, and a thirdmaterial layer has a wurtzite crystal structure. The first materiallayer may include metal nitride having an FCC crystal structure. Thefirst material layer may include zirconium nitride (ZrN), hafniumnitride (HfN), titanium nitride (TiN) or molybdenum nitride (MoN). Thesecond material layer may include metal oxide having a NaCl crystalstructure. The second material layer may include magnesium oxide (MgO)or zirconium oxide (ZrO). The third material layer may include aluminumnitride (AlN), silver iodide (AgI), zinc oxide (ZnO), cadmium sulfate(CdS), cadmium selenide (CdSe), silicon carbide (SiC), galium nitride(GaN) or boron nitride (BN).

The electronic device may further comprising a microprocessor whichincludes: a control unit configured to receive a signal including acommand from an outside of the microprocessor, and performs extracting,decoding of the command, or controlling input or output of a signal ofthe microprocessor; an operation unit configured to perform an operationbased on a result that the control unit decodes the command; and amemory unit configured to store data for performing the operation, datacorresponding to a result of performing the operation, or an address ofdata for which the operation is performed, wherein the semiconductormemory is part of the memory unit in the microprocessor.

The electronic device may further comprising a processor which includes:a core unit configured to perform, based on a command inputted from anoutside of the processor, an operation corresponding to the command, byusing data; a cache memory unit configured to store data for performingthe operation, data corresponding to a result of performing theoperation, or an address of data for which the operation is performed;and a bus interface connected between the core unit and the cache memoryunit, and configured to transmit data between the core unit and thecache memory unit, wherein the semiconductor memory is part of the cachememory unit in the processor.

The electronic device may further comprising a processing system whichincludes: a processor configured to decode a command received by theprocessor and control an operation for information based on a result ofdecoding the command; an auxiliary memory device configured to store aprogram for decoding the command and the information; a main memorydevice configured to call and store the program and the information fromthe auxiliary memory device such that the processor can perform theoperation using the program and the information when executing theprogram; and an interface device configured to perform communicationbetween at least one of the processor, the auxiliary memory device andthe main memory device and the outside, wherein the semiconductor memoryis part of the auxiliary memory device or the main memory device in theprocessing system.

The electronic device may further comprising a data storage system whichincludes: a storage device configured to store data and conserve storeddata regardless of power supply; a controller configured to controlinput and output of data to and from the storage device according to acommand inputted form an outside; a temporary storage device configuredto temporarily store data exchanged between the storage device and theoutside; and an interface configured to perform communication between atleast one of the storage device, the controller and the temporarystorage device and the outside, wherein the semiconductor memory is partof the storage device or the temporary storage device in the datastorage system.

The electronic device may further comprising a memory system whichincludes: a memory configured to store data and conserve stored dataregardless of power supply; a memory controller configured to controlinput and output of data to and from the memory according to a commandinputted form an outside; a buffer memory configured to buffer dataexchanged between the memory and the outside; and an interfaceconfigured to perform communication between at least one of the memory,the memory controller and the buffer memory and the outside, wherein thesemiconductor memory is part of the memory or the buffer memory in thememory system.

In another implementation, an electronic device may include a variableresistance element that includes a free magnetic layer having a variablemagnetization direction and exhibits different resistance values fordifferent magnetization directions in the free magnetic layer; and anunder layer formed in direct contact with the free magnetic layer of thevariable resistance element and including a plurality of material layershaving different crystal structures. The under layer may include a firstmaterial layer having an FCC (Face Centered Cubic) crystal structure anda second material layer having a NaCl crystal structure.

Further, in the electronic device in accordance with the implementation,the under layer may further include a dusting layer interposed betweenthe first material layer and the second material layer and having awurtzite crystal structure. The dusting layer may be formed as thicklyas possible within a predetermined range.

Moreover, in the electronic device in accordance with theimplementation, the under layer may further include a dusting layerinterposed between the second material layer and the free magnetic layerand having a wurtzite crystal structure. The dusting layer may be formedas thinly as possible within a predetermined range.

The dusting layer may include aluminum nitride (AlN), silver iodide(AgI), zinc oxide (ZnO), cadmium sulfate (CdS), cadmium selenide (CdSe),silicon carbide (SiC), galium nitride (GaN) or boron nitride (BN). Thefirst material layer may include metal nitride having an FCC crystalstructure. The first material layer may include zirconium nitride (ZrN),hafnium nitride (HfN), titanium nitride (TiN) or molybdenum nitride(MoN). The second material layer may include metal oxide having a NaClcrystal structure. The second material layer may include magnesium oxide(MgO) or zirconium oxide (ZrO). The free magnetic layer may be adifferent crystal structure from the under layer. The first magneticlayer may have a BCC (Body Centered Cubic) crystal structure.

These and other aspects, implementations and associated advantages aredescribed in greater detail in the drawings, the description and theclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating a variable resistanceelement in accordance with a first implementation of the presentdisclosure.

FIG. 2 is a cross-sectional view illustrating a variable resistanceelement in accordance with a second implementation of the presentdisclosure.

FIG. 3 is a graph illustrating a change in a magnetic anisotropy fieldin the free layer depending on a thickness of the dusting layer in thevariable resistance element in accordance with the two differentimplementations in FIGS. 1 and 2 of the present disclosure.

FIG. 4 is a cross-sectional view illustrating a memory device and amethod for fabricating the same in accordance with an implementation ofthe present disclosure.

FIG. 5 is a cross-sectional view illustrating a memory device and amethod for fabricating the same in accordance with anotherimplementation of the present disclosure.

FIG. 6 is an example of configuration diagram of a microprocessorimplementing memory circuitry based on the disclosed technology.

FIG. 7 is an example of configuration diagram of a processorimplementing memory circuitry based on the disclosed technology.

FIG. 8 is an example of configuration diagram of a system implementingmemory circuitry based on the disclosed technology.

FIG. 9 is an example of configuration diagram of a data storage systemimplementing memory circuitry based on the disclosed technology.

FIG. 10 is an example of configuration diagram of a memory systemimplementing memory circuitry based on the disclosed technology.

DETAILED DESCRIPTION

Various examples and implementations of the disclosed technology aredescribed below in detail with reference to the accompanying drawings.

The drawings may not be necessarily to scale and in some instances,proportions of at least some of structures in the drawings may have beenexaggerated in order to clearly illustrate certain features of thedescribed examples or implementations. In presenting a specific examplein a drawing or description having two or more layers in a multi-layerstructure, the relative positioning relationship of such layers or thesequence of arranging the layers as shown reflects a particularimplementation for the described or illustrated example and a differentrelative positioning relationship or sequence of arranging the layersmay be possible. In addition, a described or illustrated example of amulti-layer structure may not reflect all layers present in thatparticular multilayer structure (e.g., one or more additional layers maybe present between two illustrated layers). As a specific example, whena first layer in a described or illustrated multi-layer structure isreferred to as being “on” or “over” a second layer or “on” or “over” asubstrate, the first layer may be directly formed on the second layer orthe substrate but may also represent a structure where one or more otherintermediate layers may exist between the first layer and the secondlayer or the substrate.

Following implementations of the present disclosure are to provide asemiconductor memory including a variable resistance element having animproved performance and an electronic device including the same. Here,the variable resistance element may mean an element capable of beingswitched between different resistance states in response to the appliedbias (for example, a current or voltage). Therefore, the variableresistance element having an improved performance may mean the variableresistance element having an improved switching characteristic betweendifferent resistance states.

FIG. 1 is a cross-sectional view illustrating an exemplary variableresistance element in accordance with an implementation of the presentdisclosure, and FIG. 2 is a cross-sectional view illustrating anexemplary variable resistance element in accordance with anotherimplementation of the implementation of the present disclosure.

As shown in FIGS. 1 and 2, a variable resistance element 100 inaccordance with the implementation of the present disclosure may includemagnetic tunnel junction (MTJ) structure including a first magneticlayer having a variable magnetization direction, a second magnetic layerhaving a pinned magnetization direction, and a tunnel barrier layer 130interposed between the first magnetic layer and the second magneticlayer. Here, the first magnetic layer may be or include a free layer120, and the second magnetic layer may be or include a pinned layer 140.

In the MTJ structure, since the magnetization direction of the freelayer 120 is variable and can be changed by applying a current or avoltage to the MTJ to cause the change, the resistance of or across theMTJ varies as a variable resistance and exhibits different resistancevalues depending on the relative direction of the magnetization of thefree layer 120 with respect to the fixed magnetization direction of thepinned layer 140 so that the MTJ exhibits different resistance statesfor different magnetization directions of the free layer 120. Therefore,the different relative directions of the magnetization directions of thefree layer 120 and the pinned layer 140 can be used to representdifferent data or data bits and, the free layer 120 may practicallystore data according to its magnetization direction. Therefore, the freelayer 120 may be referred to as a storage layer. The magnetizationdirection of the free layer 120 may be changed by spin transfer torque.Since the magnetization direction of the pinned layer 140 is pinned, thepinned layer 140 may be compared with the free layer 120 and be referredto as a reference layer. The tunnel barrier layer 130 may serve tochange the magnetization direction of the free layer 120 by tunneling ofelectrons. In some implementations, the free layer 120 and the pinnedlayer 140 may have the magnetization direction perpendicular to asurface of each layer. For example, as indicated by arrows in drawings,the magnetization direction of the free layer 120 may be changed betweena downward direction and an upward direction, and the magnetizationdirection of the pinned layer 140 may be fixed to an upward direction.In other implementations, the free layer and the pinned layer may beconfigured to have their magnetization directions to be parallel to thelayers in the MTJ.

In response to a voltage or current applied to the variable resistanceelement 100, the magnetization direction of the free layer 120 may bechanged so as to be parallel or anti-parallel to the magnetizationdirection of the pinned layer 140. As a result, the variable resistanceelement 100 may be switched between a low resistance state and a highresistance state to store different data. That is, the variableresistance element 100 may function as a memory cell.

Each of the free layer 120 and the pinned layer 140 may have asingle-layered structure or a multi-layered structure including aferromagnetic material. Here, the free layer 120 contacting with anunder layer 110 described below may have a BCC (Body Centered Cubic)structure. Under this structural design, a magnetic anisotropy of thefree layer 120 may be improved due to the under layer 110.

In some implementations, each of the free layer 120 and the pinned layer140 may include an alloy of which a main component is Fe, Ni or Co, suchas a Co—Fe—B alloy, a Co—Fe—B-X alloy (Here, X may be or include Al, Si,Ti, V, Cr, Ni, Ga, Ge, Zr, Nb, Mo, Pd, Ag, Hf, Ta, W or Pt.), an Fe—Ptalloy, an Fe—Pd alloy, a Co—Pd alloy, a Co—Pt alloy, an Fe—Ni—Pt alloy,a Co—Fe—Pt alloy, a Co—Ni—Pt alloy, an Fe—Pd alloy, a Co—Pd alloy, aCo—Pt alloy, an Fe—Ni—Pt alloy, a Co—Fe—Pt alloy, or a Co—Ni—Pt alloy,etc. Each of the free layer 120 and the pinned layer 140 may include astack structure of Co/Pt or Co/Pd, etc. or an alternate stack structureof a magnetic material and a non-magnetic material. The tunnel barrierlayer 130 may include an insulating oxide, for example, MgO, CaO, SrO,TiO, VO, or NbO, etc.

In some implementations, the variable resistance element 100 inaccordance with this implementation may further include one or moreadditional layers performing various functions to improve acharacteristic of the MTJ structure. For example, one implementation ofthe variable resistance element includes an under layer 110, a spacerlayer 150, a magnetic correction layer 160 and a capping layer 170.However, the present disclosure is not limited thereto and otherimplementations are also possible.

The under layer 110 may be used to improve a characteristic of the layerdisposed over the under layer 110, for example, the free layer 120. Thisis because in part that the material of the free layer 120 and theunderlying material below the under layer 110 (e.g., a substrate) tendto be different materials with different material structures and suchdifference can adversely affect the final structure of the free layer120. The under layer 110 is specifically designed based on the suchdifference to provide an interfacing structure to mitigate such adverseeffect to the free layer 120. Under this design, the characteristicimproved by the under layer 110 may be a magnetic anisotropy of the freelayer 120. The under layer 110 may include a plurality of materiallayers, and each of the plurality of material layers may have adifferent crystal structure from one another. Moreover, crystalstructures of the plurality of material layers may be different from acrystal structure of the free layer 120. In some implementations, anyone of the plurality of material layers may include a dusting layer. Forthe reference, “Dusting” in material science often means a collection ofparticles or particle clusters that do not directly bind with oneanother to form a continuous material layer or structure. Instead, a“dusting layer” is a layer of particles or particle clusters that arerather loosely located from one another without any material bonding inbetween, more or less like a layer of dust on a surface in a dirty room.For example, the dusting layer may have a thin film having a very smallthickness in an atomic diameter or less. For example, the dusting layermay have a thin film having a thickness of 1 nm or less. In someimplementations, the dusting layer may have a thin film in which atomsare discontinuously arranged.

In some implementations, the under layer 110 may include a firstmaterial layer 111, a second material layer 112 and a third materiallayer 113, and the third material layer 113 may be or include thedusting layer. The second material layer 112 may be disposed over thefirst material layer 111, and the third material layer 113 may beinterposed between the first material layer 111 and the second materiallayer 112, such as the configuration in FIG. 1. in which the free layer120 is formed on top of the second material layer 112 without being indirect contact with the dusting layer 113 which is underneath the secondmaterial layer 112. In the different configuration in FIG. 2, thedusting layer is located on top of the first and second material layers111 and 112 and is between the second material layer 112 and the freelayer 120 to be directly under the free layer 120. Those two differentconfigurations for the under layer 110 are designed to provide aninterfacing material structure between the free layer 120 and thematerial structure underneath the under layer 110.

The first material layer 111 may be used to improve a crystalorientation with respect to the layer disposed over the first materiallayer 111, for example, the second material layer 112. On this account,the first material layer 111 may have an FCC (Face Centered Cubic)crystal structure. In some implementations, the first material layer 111may include metal nitride having an FCC crystal structure. For example,the first material layer 111 may include zirconium nitride (ZrN),hafnium nitride (HfN), titanium nitride (TiN), or molybdenum nitride(MoN).

The second material layer 112 may be used to improve a crystalorientation with respect to the layer disposed over the second materiallayer 112, for example, the free layer 120. On this account, the secondmaterial layer 112 may have a NaCl crystal structure. In someimplementations, the second material layer 112 may include metal oxidehaving a NaCl crystal structure. For example, the second material layer112 may include magnesium oxide (MgO) or zirconium oxide (ZrO).

The third material layer 113 may serve to reduce a lattice mismatchbetween the layers disposed over and below the third material layer 113in both designs in FIGS. 1 and 2 but have different roles in the twodifferent designs. For both designs, the third material layer 113 mayhave a wurtzite crystal structure. In some implementations, the thirdmaterial layer 113 may include aluminum nitride (AlN), silver iodide(AgI), zinc oxide (ZnO), cadmium sulfate (CdS), cadmium selenide (CdSe),silicon carbide (SiC), galium nitride (GaN) or boron nitride (BN), whichhave wurtzite crystal structures.

Referring to the first implementation of the under layer 110 in FIG. 1in which the second material layer 112 is in direct contact with thefree layer 120 as shown in the sequentially stacked structure for thevariable resistance element 100, and the under layer 110 with amulti-stack structure including the first material layer 111, the thirdmaterial layer 113 and the second material layer 112, the third materiallayer 113 may serve to reduce a lattice mismatch between the firstmaterial layer 111 and the second material layer 112. That is, the thirdmaterial layer 113 may serve to improve a crystal orientation of thewhole structure of the under layer 110. Since the under layer 110 mayfunction as a seed layer with respect to the free layer 120, acrystallinity of the free layer 120 can be improved as a crystalorientation of the under layer 110 is improved.

As a result, a magnetic anisotropy of the free layer 120 can beimproved. In some implementations, when the third material layer 113,which can be, for example, a dusting layer, is interposed between thefirst material layer 111 and the second material layer 112, the thirdmaterial layer 113 preferably has a thickness as large as possiblewithin a predetermined range. Here, the predetermined range may mean athickness which enables the third material layer 113 to function as thedusting layer, for example, a thickness of 1 nm or less. This will befurther explained with reference to FIG. 3.

Then, referring to the second implementation of the under layer 110 inFIG. 2 where the third material layer 113 (e.g., a dusting layer) is indirect contact with the free layer 120 as shown in the sequentiallystacked structure for the variable resistance element 100 and themulti-stack structure under layer 110 including the first material layer111, the second material layer 112 and the third material layer 113, thethird material layer 113 (e.g., a dusting layer) may serve to reduce alattice mismatch between the second material layer 112 and the freelayer 120. Thus, a lattice mismatch can be decreased at the interfacebetween the under layer 110 and the free layer 120 so as to improve acrystallinity of the free layer 120. As a result, a magnetic anisotropyof the free layer 120 can be improved. In some implementations, when thethird material layer 113, for example, the dusting layer is interposedbetween the second material layer 112 and the free layer 120, the thirdmaterial layer 113 preferably has a thickness as small as possiblewithin a predetermined range. This will also be explained with referenceto FIG. 3.

The magnetic correction layer 160 may serve to offset or reduce aninfluence of a stray field generated by the pinned layer 140. In thiscase, the influence of the stray filed of the pinned layer 140 on thefree layer 120 is decreased so that a bias magnetic field in the freelayer 120 can be reduced. The magnetic correction layer 160 may have amagnetization direction anti-parallel to the magnetization direction ofthe pinned layer 140. In the implementations, when the magnetizationdirection of the pinned layer 140 is an upward direction, themagnetization direction of the magnetic correction layer 160 may be adownward direction. On the contrary, when the magnetization direction ofthe pinned layer 140 is a downward direction, the magnetizationdirection of the magnetic correction layer 160 may be an upwarddirection. Meanwhile, the magnetic correction layer 160 may have amagnetization direction parallel to the magnetization direction of thepinned layer 140.

The spacer layer 150 may be interposed between the magnetic correctionlayer 160 and the pinned layer 140, and be used to provide an interlayerexchange coupling therebetween. The spacer layer 150 may include ametallic non-magnetic material such as Cr, Ru, Ir, or Rh, etc.

The capping layer 170 may function as a hard mask for patterning thevariable resistance element 100. The capping layer 170 may includevarious conductive materials such as a metal, etc.

The variable resistance element 100 in accordance with theimplementations of the present disclosure described above includes theunder layer 110 including the plurality of material layers havingdifferent crystal structures so as to improve characteristics of thevariable resistance element 100.

FIG. 3 is a graph illustrating a change in a magnetic anisotropy fieldin the free layer depending on a thickness of the dusting layer in thevariable resistance element in accordance with the implementations ofthe present disclosure.

In FIG. 3, a horizontal axis represents a thickness of the dustinglayer, that is, a thickness of the third material layer 113, and avertical axis represents a normalized magnetic anisotropy field (Hk) inthe free layer 120. To obtain data necessary for FIG. 3, aluminumnitride (AlN) has been used for the third material layer 113. Thecomparative example represents a case in which the under layer 110 doesnot include the third material layer 113.

Referring to FIGS. 1 and 3, when the under layer 110 has a multi-stackstructure where the first material layer 111, the third material layer113 and the second material layer 112 are sequentially stacked in a waythat the second material layer 112 is in direct contact with the freelayer 120, it can be confirmed that a magnetic anisotropy of the freelayer 120 is improved as a thickness of the third material layer 113between the first and second material layers 112 and 111 is increasedwithin a thickness range of the dusting layer, for example, from about0.5 Å to about 2 Å. The test results in FIG. 3 demonstrate this aspectof the under layer 110 in FIG. 1.

In the other under layer design in FIG. 2 where the under layer 110 hasa multi-stack structure having the first material layer 111, the secondmaterial layer 112 and the third material layer 113 that aresequentially stacked in a way that the third material layer 113 isdirectly underneath the free layer 120 and on top of the layers 111 and112, it can be confirmed that a magnetic anisotropy of the free layer120 is improved as a thickness of the third material layer 113 isdecreased within a thickness range which may be represented by thedusting layer, that is, within a predetermined range. The test resultsin FIG. 3 demonstrate this aspect of the under layer 110 in FIG. 1

From FIG. 3, it can be recognized that the magnetic anisotropy fieldvalues of the free layer 120 differently change with a thickness of thethird material layer 113 depending on the position of the third materiallayer 113. This is because a crystal structure of the material layerdisposed below the third material layer 113 is changed depending on theposition of the third material layer 113. When the third material layer113 is formed over the first material layer 111, the first materiallayer 111 disposed below the third material layer 113 has an FCC crystalstructure. However, when the third material layer 113 is formed over thesecond material layer 112, the second material layer 112 disposed belowthe third material layer 113 has a NaCl crystal structure. As such,since the crystal structures of the material layer disposed below thethird material layer 113 are different from each other, thecrystallinity of the free layer 120 have been affected by differentinfluences in the two cases.

In accordance with implementation, it is possible to improvecharacteristics of the variable resistance element and thus, improvecharacteristics of the semiconductor memory including the variableresistance element and the electronic device including the semiconductordevice.

The variable resistance element in accordance with the implementationsof the present disclosure, for example, the variable resistance element100 of FIG. 1 may be provided in plural to form a cell array. The cellarray may include various components such as lines, or elements, etc. todrive the variable resistance element 100. This will be exemplarilydescribed with reference to FIGS. 4 and 5.

FIG. 4 is a cross-sectional view illustrating an exemplary memory deviceand a method for fabricating the same in accordance with animplementation of the present disclosure.

Referring to FIG. 4, the memory device of this implementation mayinclude a substrate 500, a lower contact 520, a variable resistanceelement 100 and an upper contact 550. The substrate 500 may include aspecific structure (not shown) which is required, for example, atransistor controlling an access to the variable resistance element 100.The lower contact 520 may be disposed over the substrate 500, and couplea lower end of the variable resistance element 100 with a portion of thesubstrate 500, for example, a drain of the transistor. The upper contact550 may be disposed over the variable resistance element 100, and couplean upper end of the variable resistance element 100 with a certain line(not shown), for example, a bit line.

The above memory device may be fabricated by following processes.

First, the substrate 500 in which the transistor is formed may beprovided, and then, a first interlayer dielectric layer 510 may beformed over the substrate 500. Subsequently, the lower contact 520 maybe formed by selectively etching the first interlayer dielectric layer510 to form a hole exposing a portion of the substrate 500 and fillingthe hole with a conductive material. Then, the variable resistanceelement 100 may be formed by forming material layers for the variableresistance element 100 over the first interlayer dielectric layer 510and the lower contact 520, and selectively etching the material layers.A second interlayer dielectric layer 530 may be formed by filling spacesamong the variable resistance elements 100 with an insulating material.Then, a third interlayer dielectric layer 340 may be formed over thevariable resistance element 100 and the second interlayer dielectriclayer 530, and then, the upper contact 550 penetrating through the thirdinterlayer dielectric layer 530 and coupled to the upper end of thevariable resistance element 100 may be formed.

In the memory device of this implementation, all layers included in thevariable resistance element 100 may have sidewalls aligned with eachother. This is because the variable resistance element 100 may be formedby an etching process using a single mask.

However, unlike the implementation of FIG. 4, a portion of the variableresistance element 100 and a remaining portion of the variableresistance element 100 may be patterned individually. This will beexemplarily shown in FIG. 5.

FIG. 5 is a cross-sectional view illustrating a memory device and amethod for fabricating the same in accordance with anotherimplementation of the present disclosure. Differences from theimplementation of FIG. 4 will be mainly described.

Referring to FIG. 5, in the memory device of this implementation, aportion of the variable resistance element 100, for example, an underlayer 110 may have a sidewall which is not aligned with sidewalls ofremaining layers of the variable resistance element 100. The under layer110 may have a sidewall which is aligned with a sidewall of a lowercontact 620.

The above memory device may be fabricated by following processes.

First, a first interlayer dielectric layer 610 may be formed over asubstrate 600, and then, a hole H exposing a portion of the substrate600 may be formed by selectively etching the first interlayer dielectriclayer 610. Then, the lower contact 620 filled in a lower portion of thehole H may be formed. Specifically, the lower contact 620 may be formedby forming a conductive material covering a resultant structure in whichthe hole H is formed, and removing a portion of the conductive materialby an etch back process, etc, until the conductive material has a targetheight. Then, the under layer 110 filled in a remaining space of thehole H in which the lower contact 620 is formed may be formed. Forexample, the under layer 110 may be formed by forming a material layerwhich includes a light metal and covers a resultant structure in whichthe lower contact 620 is formed, and performing a planarization process,for example, a CMP (Chemical Mechanical Polishing) process until a topsurface of the first interlayer dielectric layer 610 is exposed. Then,the remaining portion of the variable resistance element 100 may beformed by forming material layers for the remaining layers of thevariable resistance element 100, except for the under layer 110, andselectively etching the material layers. Following processes aresubstantially same as the implementation of FIG. 4.

In this implementation, since a thickness to be etched for forming thevariable resistance element 100 decreases, a difficulty of an etchingprocess can be reduced.

Also, in this implementation, a case that the under layer 110 is filledin the hole H is described. However, other implementations are alsopossible. For example, another portion of the variable resistanceelement 100 can be further filled in the hole H.

The semiconductor memory in accordance with the implementation of thepresent disclosure may be applied to diverse electronic devices orsystems. FIGS. 6 to 10 show some examples of electronic devices orsystems that can implement the semiconductor memory disclosed herein.

Referring to FIG. 6, a microprocessor 1000 may perform tasks forcontrolling and tuning a series of processes of receiving data fromvarious external devices, processing the data, and outputting processingresults to external devices. The microprocessor 1000 may include amemory unit 1010, an operation unit 1020, a control unit 1030, and soon. The microprocessor 1000 may be various data processing units such asa central processing unit (CPU), a graphic processing unit (GPU), adigital signal processor (DSP) and an application processor (AP).

The memory unit 1010 is a part which stores data in the microprocessor1000, as a processor register, register or the like. The memory unit1010 may include a data register, an address register, a floating pointregister and so on. Besides, the memory unit 1010 may include variousregisters. The memory unit 1010 may perform the function of temporarilystoring data for which operations are to be performed by the operationunit 1020, result data of performing the operations and addresses wheredata for performing of the operations are stored.

The memory unit 1010 may include one or more of the above-describedsemiconductor devices in accordance with the implementations. The memoryunit 1010 may include semiconductor memory which includes a variableresistance element. The variable resistance element may include an underlayer including a plurality of material layers, each of the plurality ofmaterial layers having a different crystal structure from each other, afirst magnetic layer formed over the under layer and having a variablemagnetization direction, a tunnel barrier layer formed over the firstmagnetic layer, and a second magnetic layer formed over the tunnelbarrier layer and having a pinned magnetization direction. The underlayer may include a first material layer, a second material layer, and athird material layer which have different crystal structures from eachother, wherein the third material layer may include a dusting layer. Byproviding the under layer, it is possible to improve characteristics ofthe variable resistance element. Therefore, the semiconductor memorywith improved operation characteristics may be provided. Through this,the memory unit 1010 and the microprocessor 1000 may have improvedreliability.

The operation unit 1020 may perform four arithmetical operations orlogical operations according to results that the control unit 1030decodes commands. The operation unit 1020 may include at least onearithmetic logic unit (ALU) and so on.

The control unit 1030 may receive signals from the memory unit 1010, theoperation unit 1020 and an external device of the microprocessor 1000,perform extraction, decoding of commands, and controlling input andoutput of signals of the microprocessor 1000, and execute processingrepresented by programs.

The microprocessor 1000 according to the present implementation mayadditionally include a cache memory unit 1040 which can temporarilystore data to be inputted from an external device other than the memoryunit 1010 or to be outputted to an external device. In this case, thecache memory unit 1040 may exchange data with the memory unit 1010, theoperation unit 1020 and the control unit 1030 through a bus interface1050.

FIG. 7 is an example of configuration diagram of a processorimplementing memory circuitry based on the disclosed technology.

Referring to FIG. 7, a processor 1100 may improve performance andrealize multi-functionality by including various functions other thanthose of a microprocessor which performs tasks for controlling andtuning a series of processes of receiving data from various externaldevices, processing the data, and outputting processing results toexternal devices. The processor 1100 may include a core unit 1110 whichserves as the microprocessor, a cache memory unit 1120 which serves tostoring data temporarily, and a bus interface 1130 for transferring databetween internal and external devices. The processor 1100 may includevarious system-on-chips (SoCs) such as a multi-core processor, a graphicprocessing unit (GPU) and an application processor (AP).

The core unit 1110 of the present implementation is a part whichperforms arithmetic logic operations for data inputted from an externaldevice, and may include a memory unit 1111, an operation unit 1112 and acontrol unit 1113.

The memory unit 1111 is a part which stores data in the processor 1100,as a processor register, a register or the like. The memory unit 1111may include a data register, an address register, a floating pointregister and so on. Besides, the memory unit 1111 may include variousregisters. The memory unit 1111 may perform the function of temporarilystoring data for which operations are to be performed by the operationunit 1112, result data of performing the operations and addresses wheredata for performing of the operations are stored. The operation unit1112 is a part which performs operations in the processor 1100. Theoperation unit 1112 may perform four arithmetical operations, logicaloperations, according to results that the control unit 1113 decodescommands, or the like. The operation unit 1112 may include at least onearithmetic logic unit (ALU) and so on. The control unit 1113 may receivesignals from the memory unit 1111, the operation unit 1112 and anexternal device of the processor 1100, perform extraction, decoding ofcommands, controlling input and output of signals of processor 1100, andexecute processing represented by programs.

The cache memory unit 1120 is a part which temporarily stores data tocompensate for a difference in data processing speed between the coreunit 1110 operating at a high speed and an external device operating ata low speed. The cache memory unit 1120 may include a primary storagesection 1121, a secondary storage section 1122 and a tertiary storagesection 1123. In general, the cache memory unit 1120 includes theprimary and secondary storage sections 1121 and 1122, and may includethe tertiary storage section 1123 in the case where high storagecapacity is required. As the occasion demands, the cache memory unit1120 may include an increased number of storage sections. That is tosay, the number of storage sections which are included in the cachememory unit 1120 may be changed according to a design. The speeds atwhich the primary, secondary and tertiary storage sections 1121, 1122and 1123 store and discriminate data may be the same or different. Inthe case where the speeds of the respective storage sections 1121, 1122and 1123 are different, the speed of the primary storage section 1121may be largest. At least one storage section of the primary storagesection 1121, the secondary storage section 1122 and the tertiarystorage section 1123 of the cache memory unit 1120 may include one ormore of the above-described semiconductor devices in accordance with theimplementations. For example, the cache memory unit 1120 may includesemiconductor memory which includes a variable resistance element. Thevariable resistance element may include an under layer including aplurality of material layers, each of the plurality of material layershaving a different crystal structure from each other, a first magneticlayer formed over the under layer and having a variable magnetizationdirection, a tunnel barrier layer formed over the first magnetic layer,and a second magnetic layer formed over the tunnel barrier layer andhaving a pinned magnetization direction. The under layer may include afirst material layer, a second material layer, and a third materiallayer which have different crystal structures from each other, whereinthe third material layer may include a dusting layer. By providing theunder layer, it is possible to improve characteristics of the variableresistance element. Therefore, the semiconductor memory with improvedoperation characteristics may be provided. Through this, the cachememory unit 1120 and the processor 1100 may have improved reliability.

Although it was shown in FIG. 7 that all the primary, secondary andtertiary storage sections 1121, 1122 and 1123 are configured inside thecache memory unit 1120, it is to be noted that all the primary,secondary and tertiary storage sections 1121, 1122 and 1123 of the cachememory unit 1120 may be configured outside the core unit 1110 and maycompensate for a difference in data processing speed between the coreunit 1110 and the external device. Meanwhile, it is to be noted that theprimary storage section 1121 of the cache memory unit 1120 may bedisposed inside the core unit 1110 and the secondary storage section1122 and the tertiary storage section 1123 may be configured outside thecore unit 1110 to strengthen the function of compensating for adifference in data processing speed. In another implementation, theprimary and secondary storage sections 1121, 1122 may be disposed insidethe core units 1110 and tertiary storage sections 1123 may be disposedoutside core units 1110.

The bus interface 1130 is a part which connects the core unit 1110, thecache memory unit 1120 and external device and allows data to beefficiently transmitted.

The processor 1100 according to the present implementation may include aplurality of core units 1110, and the plurality of core units 1110 mayshare the cache memory unit 1120. The plurality of core units 1110 andthe cache memory unit 1120 may be directly connected or be connectedthrough the bus interface 1130. The plurality of core units 1110 may beconfigured in the same way as the above-described configuration of thecore unit 1110. In the case where the processor 1100 includes theplurality of core unit 1110, the primary storage section 1121 of thecache memory unit 1120 may be configured in each core unit 1110 incorrespondence to the number of the plurality of core units 1110, andthe secondary storage section 1122 and the tertiary storage section 1123may be configured outside the plurality of core units 1110 in such a wayas to be shared through the bus interface 1130. The processing speed ofthe primary storage section 1121 may be larger than the processingspeeds of the secondary and tertiary storage section 1122 and 1123. Inanother implementation, the primary storage section 1121 and thesecondary storage section 1122 may be configured in each core unit 1110in correspondence to the number of the plurality of core units 1110, andthe tertiary storage section 1123 may be configured outside theplurality of core units 1110 in such a way as to be shared through thebus interface 1130.

The processor 1100 according to the present implementation may furtherinclude an embedded memory unit 1140 which stores data, a communicationmodule unit 1150 which can transmit and receive data to and from anexternal device in a wired or wireless manner, a memory control unit1160 which drives an external memory device, and a media processing unit1170 which processes the data processed in the processor 1100 or thedata inputted from an external input device and outputs the processeddata to an external interface device and so on. Besides, the processor1100 may include a plurality of various modules and devices. In thiscase, the plurality of modules which are added may exchange data withthe core units 1110 and the cache memory unit 1120 and with one another,through the bus interface 1130.

The embedded memory unit 1140 may include not only a volatile memory butalso a nonvolatile memory. The volatile memory may include a DRAM(dynamic random access memory), a mobile DRAM, an SRAM (static randomaccess memory), and a memory with similar functions to above mentionedmemories, and so on. The nonvolatile memory may include a ROM (read onlymemory), a NOR flash memory, a NAND flash memory, a phase change randomaccess memory (PRAM), a resistive random access memory (RRAM), a spintransfer torque random access memory (STTRAM), a magnetic random accessmemory (MRAM), a memory with similar functions.

The communication module unit 1150 may include a module capable of beingconnected with a wired network, a module capable of being connected witha wireless network and both of them. The wired network module mayinclude a local area network (LAN), a universal serial bus (USB), anEthernet, power line communication (PLC) such as various devices whichsend and receive data through transmit lines, and so on. The wirelessnetwork module may include Infrared Data Association (IrDA), codedivision multiple access (CDMA), time division multiple access (TDMA),frequency division multiple access (FDMA), a wireless LAN, Zigbee, aubiquitous sensor network (USN), Bluetooth, radio frequencyidentification (RFID), long term evolution (LTE), near fieldcommunication (NFC), a wireless broadband Internet (Wibro), high speeddownlink packet access (HSDPA), wideband CDMA (WCDMA), ultra wideband(UWB) such as various devices which send and receive data withouttransmit lines, and so on.

The memory control unit 1160 is to administrate and process datatransmitted between the processor 1100 and an external storage deviceoperating according to a different communication standard. The memorycontrol unit 1160 may include various memory controllers, for example,devices which may control IDE (Integrated Device Electronics), SATA(Serial Advanced Technology Attachment), SCSI (Small Computer SystemInterface), RAID (Redundant Array of Independent Disks), an SSD (solidstate disk), eSATA (External SATA), PCMCIA (Personal Computer MemoryCard International Association), a USB (universal serial bus), a securedigital (SD) card, a mini secure digital (mSD) card, a micro securedigital (micro SD) card, a secure digital high capacity (SDHC) card, amemory stick card, a smart media (SM) card, a multimedia card (MMC), anembedded MMC (eMMC), a compact flash (CF) card, and so on.

The media processing unit 1170 may process the data processed in theprocessor 1100 or the data inputted in the forms of image, voice andothers from the external input device and output the data to theexternal interface device. The media processing unit 1170 may include agraphic processing unit (GPU), a digital signal processor (DSP), a highdefinition audio device (HD audio), a high definition multimediainterface (HDMI) controller, and so on.

FIG. 8 is an example of configuration diagram of a system implementingmemory circuitry based on the disclosed technology.

Referring to FIG. 8, a system 1200 as an apparatus for processing datamay perform input, processing, output, communication, storage, etc. toconduct a series of manipulations for data. The system 1200 may includea processor 1210, a main memory device 1220, an auxiliary memory device1230, an interface device 1240, and so on. The system 1200 of thepresent implementation may be various electronic systems which operateusing processors, such as a computer, a server, a PDA (personal digitalassistant), a portable computer, a web tablet, a wireless phone, amobile phone, a smart phone, a digital music player, a PMP (portablemultimedia player), a camera, a global positioning system (GPS), a videocamera, a voice recorder, a telematics, an audio visual (AV) system, asmart television, and so on.

The processor 1210 may decode inputted commands and processes operation,comparison, etc. for the data stored in the system 1200, and controlsthese operations. The processor 1210 may include a microprocessor unit(MPU), a central processing unit (CPU), a single/multi-core processor, agraphic processing unit (GPU), an application processor (AP), a digitalsignal processor (DSP), and so on.

The main memory device 1220 is a storage which can temporarily store,call and execute program codes or data from the auxiliary memory device1230 when programs are executed and can conserve memorized contents evenwhen power supply is cut off. The main memory device 1220 may includeone or more of the above-described semiconductor devices in accordancewith the implementations. For example, the main memory device 1220 mayinclude semiconductor memory which includes a variable resistanceelement. The variable resistance element may include an under layerincluding a plurality of material layers, each of the plurality ofmaterial layers having a different crystal structure from each other, afirst magnetic layer formed over the under layer and having a variablemagnetization direction, a tunnel barrier layer formed over the firstmagnetic layer, and a second magnetic layer formed over the tunnelbarrier layer and having a pinned magnetization direction. The underlayer may include a first material layer, a second material layer, and athird material layer which have different crystal structures from eachother, wherein the third material layer may include a dusting layer. Byproviding the under layer, it is possible to improve characteristics ofthe variable resistance element. Therefore, the semiconductor memorywith improved operation characteristics may be provided. Through this,the main memory device 1220 and the system 1200 may have improvedreliability.

Also, the main memory device 1220 may further include a static randomaccess memory (SRAM), a dynamic random access memory (DRAM), and so on,of a volatile memory type in which all contents are erased when powersupply is cut off. Unlike this, the main memory device 1220 may notinclude the semiconductor devices according to the implementations, butmay include a static random access memory (SRAM), a dynamic randomaccess memory (DRAM), and so on, of a volatile memory type in which allcontents are erased when power supply is cut off.

The auxiliary memory device 1230 is a memory device for storing programcodes or data. While the speed of the auxiliary memory device 1230 isslower than the main memory device 1220, the auxiliary memory device1230 can store a larger amount of data. The auxiliary memory device 1230may include one or more of the above-described semiconductor devices inaccordance with the implementations. For example, the auxiliary memorydevice 1230 may include semiconductor memory which includes a variableresistance element. The variable resistance element may include an underlayer including a plurality of material layers, each of the plurality ofmaterial layers having a different crystal structure from each other, afirst magnetic layer formed over the under layer and having a variablemagnetization direction, a tunnel barrier layer formed over the firstmagnetic layer, and a second magnetic layer formed over the tunnelbarrier layer and having a pinned magnetization direction. The underlayer may include a first material layer, a second material layer, and athird material layer which have different crystal structures from eachother, wherein the third material layer may include a dusting layer. Byproviding the under layer, it is possible to improve characteristics ofthe variable resistance element. Therefore, the semiconductor memorywith improved operation characteristics may be provided. Through this,the auxiliary memory device 1230 and the system 1200 may have improvedreliability.

Also, the auxiliary memory device 1230 may further include a datastorage system (see the reference numeral 1300 of FIG. 9) such as amagnetic tape using magnetism, a magnetic disk, a laser disk usingoptics, a magneto-optical disc using both magnetism and optics, a solidstate disk (SSD), a USB memory (universal serial bus memory), a securedigital (SD) card, a mini secure digital (mSD) card, a micro securedigital (micro SD) card, a secure digital high capacity (SDHC) card, amemory stick card, a smart media (SM) card, a multimedia card (MMC), anembedded MMC (eMMC), a compact flash (CF) card, and so on. Unlike this,the auxiliary memory device 1230 may not include the semiconductordevices according to the implementations, but may include data storagesystems (see the reference numeral 1300 of FIG. 9) such as a magnetictape using magnetism, a magnetic disk, a laser disk using optics, amagneto-optical disc using both magnetism and optics, a solid state disk(SSD), a USB memory (universal serial bus memory), a secure digital (SD)card, a mini secure digital (mSD) card, a micro secure digital (microSD) card, a secure digital high capacity (SDHC) card, a memory stickcard, a smart media (SM) card, a multimedia card (MMC), an embedded MMC(eMMC), a compact flash (CF) card, and so on.

The interface device 1240 may be to perform exchange of commands anddata between the system 1200 of the present implementation and anexternal device. The interface device 1240 may be a keypad, a keyboard,a mouse, a speaker, a mike, a display, various human interface devices(HIDs), a communication device, and so on. The communication device mayinclude a module capable of being connected with a wired network, amodule capable of being connected with a wireless network and both ofthem. The wired network module may include a local area network (LAN), auniversal serial bus (USB), an Ethernet, power line communication (PLC),such as various devices which send and receive data through transmitlines, and so on. The wireless network module may include Infrared DataAssociation (IrDA), code division multiple access (CDMA), time divisionmultiple access (TDMA), frequency division multiple access (FDMA), awireless LAN, Zigbee, a ubiquitous sensor network (USN), Bluetooth,radio frequency identification (RFID), long term evolution (LTE), nearfield communication (NFC), a wireless broadband Internet (Wibro), highspeed downlink packet access (HSDPA), wideband CDMA (WCDMA), ultrawideband (UWB), such as various devices which send and receive datawithout transmit lines, and so on.

FIG. 9 is an example of configuration diagram of a data storage systemimplementing memory circuitry based on the disclosed technology.

Referring to FIG. 9, a data storage system 1300 may include a storagedevice 1310 which has a nonvolatile characteristic as a component forstoring data, a controller 1320 which controls the storage device 1310,an interface 1330 for connection with an external device, and atemporary storage device 1340 for storing data temporarily. The datastorage system 1300 may be a disk type such as a hard disk drive (HDD),a compact disc read only memory (CDROM), a digital versatile disc (DVD),a solid state disk (SSD), and so on, and a card type such as a USBmemory (universal serial bus memory), a secure digital (SD) card, a minisecure digital (mSD) card, a micro secure digital (micro SD) card, asecure digital high capacity (SDHC) card, a memory stick card, a smartmedia (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), acompact flash (CF) card, and so on.

The storage device 1310 may include a nonvolatile memory which storesdata semi-permanently. The nonvolatile memory may include a ROM (readonly memory), a NOR flash memory, a NAND flash memory, a phase changerandom access memory (PRAM), a resistive random access memory (RRAM), amagnetic random access memory (MRAM), and so on.

The controller 1320 may control exchange of data between the storagedevice 1310 and the interface 1330. To this end, the controller 1320 mayinclude a processor 1321 for performing an operation for, processingcommands inputted through the interface 1330 from an outside of the datastorage system 1300 and so on.

The interface 1330 is to perform exchange of commands and data betweenthe data storage system 1300 and the external device. In the case wherethe data storage system 1300 is a card type, the interface 1330 may becompatible with interfaces which are used in devices, such as a USBmemory (universal serial bus memory), a secure digital (SD) card, a minisecure digital (mSD) card, a micro secure digital (micro SD) card, asecure digital high capacity (SDHC) card, a memory stick card, a smartmedia (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), acompact flash (CF) card, and so on, or be compatible with interfaceswhich are used in devices similar to the above mentioned devices. In thecase where the data storage system 1300 is a disk type, the interface1330 may be compatible with interfaces, such as IDE (Integrated DeviceElectronics), SATA (Serial Advanced Technology Attachment), SCSI (SmallComputer System Interface), eSATA (External SATA), PCMCIA (PersonalComputer Memory Card International Association), a USB (universal serialbus), and so on, or be compatible with the interfaces which are similarto the above mentioned interfaces. The interface 1330 may be compatiblewith one or more interfaces having a different type from each other.

The temporary storage device 1340 can store data temporarily forefficiently transferring data between the interface 1330 and the storagedevice 1310 according to diversifications and high performance of aninterface with an external device, a controller and a system. Thetemporary storage device 1340 for temporarily storing data may includeone or more of the above-described semiconductor devices in accordancewith the implementations. For example, the temporary storage device 1340may include semiconductor memory which includes a variable resistanceelement. The variable resistance element may include an under layerincluding a plurality of material layers, each of the plurality ofmaterial layers having a different crystal structure from each other, afirst magnetic layer formed over the under layer and having a variablemagnetization direction, a tunnel barrier layer formed over the firstmagnetic layer, and a second magnetic layer formed over the tunnelbarrier layer and having a pinned magnetization direction. The underlayer may include a first material layer, a second material layer, and athird material layer which have different crystal structures from eachother, wherein the third material layer may include a dusting layer. Byproviding the under layer, it is possible to improve characteristics ofthe variable resistance element. Therefore, the semiconductor memorywith improved operation characteristics may be provided. Through this,the temporary storage device 1340 and the data storage system 1300 mayhave improved reliability.

FIG. 10 is an example of configuration diagram of a memory systemimplementing memory circuitry based on the disclosed technology.

Referring to FIG. 10, a memory system 1400 may include a memory 1410which has a nonvolatile characteristic as a component for storing data,a memory controller 1420 which controls the memory 1410, an interface1430 for connection with an external device, and so on. The memorysystem 1400 may be a card type such as a solid state disk (SSD), a USBmemory (universal serial bus memory), a secure digital (SD) card, a minisecure digital (mSD) card, a micro secure digital (micro SD) card, asecure digital high capacity (SDHC) card, a memory stick card, a smartmedia (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), acompact flash (CF) card, and so on.

The memory 1410 for storing data may include one or more of theabove-described semiconductor devices in accordance with theimplementations. For example, the memory 1410 may include semiconductormemory which includes a variable resistance element. The variableresistance element may include an under layer including a plurality ofmaterial layers, each of the plurality of material layers having adifferent crystal structure from each other, a first magnetic layerformed over the under layer and having a variable magnetizationdirection, a tunnel barrier layer formed over the first magnetic layer,and a second magnetic layer formed over the tunnel barrier layer andhaving a pinned magnetization direction. The under layer may include afirst material layer, a second material layer, and a third materiallayer which have different crystal structures from each other, whereinthe third material layer may include a dusting layer. By providing theunder layer, it is possible to improve characteristics of the variableresistance element. Therefore, the semiconductor memory with improvedoperation characteristics may be provided. Through this, the memory 1410and the memory system 1400 may have improved reliability.

Also, the memory 1410 according to the present implementation mayfurther include a ROM (read only memory), a NOR flash memory, a NANDflash memory, a phase change random access memory (PRAM), a resistiverandom access memory (RRAM), a magnetic random access memory (MRAM), andso on, which have a nonvolatile characteristic.

The memory controller 1420 may control exchange of data between thememory 1410 and the interface 1430. To this end, the memory controller1420 may include a processor 1421 for performing an operation for andprocessing commands inputted through the interface 1430 from an outsideof the memory system 1400.

The interface 1430 is to perform exchange of commands and data betweenthe memory system 1400 and the external device. The interface 1430 maybe compatible with interfaces which are used in devices, such as a USBmemory (universal serial bus memory), a secure digital (SD) card, a minisecure digital (mSD) card, a micro secure digital (micro SD) card, asecure digital high capacity (SDHC) card, a memory stick card, a smartmedia (SM) card, a multimedia card (MMC), an embedded MMC (eMMC), acompact flash (CF) card, and so on, or be compatible with interfaceswhich are used in devices similar to the above mentioned devices. Theinterface 1430 may be compatible with one or more interfaces having adifferent type from each other.

The memory system 1400 according to the present implementation mayfurther include a buffer memory 1440 for efficiently transferring databetween the interface 1430 and the memory 1410 according todiversification and high performance of an interface with an externaldevice, a memory controller and a memory system. For example, the buffermemory 1440 may include semiconductor memory which includes a variableresistance element. The variable resistance element may include an underlayer including a plurality of material layers, each of the plurality ofmaterial layers having a different crystal structure from each other, afirst magnetic layer formed over the under layer and having a variablemagnetization direction, a tunnel barrier layer formed over the firstmagnetic layer, and a second magnetic layer formed over the tunnelbarrier layer and having a pinned magnetization direction. The underlayer may include a first material layer, a second material layer, and athird material layer which have different crystal structures from eachother, wherein the third material layer may include a dusting layer. Byproviding the under layer, it is possible to improve characteristics ofthe variable resistance element. Therefore, the semiconductor memorywith improved operation characteristics may be provided. Through this,the buffer memory 1440 and the memory system 1400 may have improvedreliability.

Moreover, the buffer memory 1440 according to the present implementationmay further include an SRAM (static random access memory), a DRAM(dynamic random access memory), and so on, which have a volatilecharacteristic, and a phase change random access memory (PRAM), aresistive random access memory (RRAM), a spin transfer torque randomaccess memory (STTRAM), a magnetic random access memory (MRAM), and soon, which have a nonvolatile characteristic. Unlike this, the buffermemory 1440 may not include the semiconductor devices according to theimplementations, but may include an SRAM (static random access memory),a DRAM (dynamic random access memory), and so on, which have a volatilecharacteristic, and a phase change random access memory (PRAM), aresistive random access memory (RRAM), a spin transfer torque randomaccess memory (STTRAM), a magnetic random access memory (MRAM), and soon, which have a nonvolatile characteristic.

Features in the above examples of electronic devices or systems in FIGS.11 to 15 based on the memory devices disclosed in this document may beimplemented in various devices, systems or applications. Some examplesinclude mobile phones or other portable communication devices, tabletcomputers, notebook or laptop computers, game machines, smart TV sets,TV set top boxes, multimedia servers, digital cameras with or withoutwireless communication functions, wrist watches or other wearabledevices with wireless communication capabilities.

While this patent document contains many specifics, these should not beconstrued as limitations on the scope of any invention or of what may beclaimed, but rather as descriptions of features that may be specific toparticular embodiments of particular inventions. Certain features thatare described in this patent document in the context of separateembodiments can also be implemented in combination in a singleembodiment. Conversely, various features that are described in thecontext of a single embodiment can also be implemented in multipleembodiments separately or in any suitable subcombination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Moreover, the separation of various system components in theembodiments described in this patent document should not be understoodas requiring such separation in all embodiments.

Only a few implementations and examples are described. Otherimplementations, enhancements and variations can be made based on whatis described and illustrated in this patent document.

1. An electronic device comprising a semiconductor memory, wherein thesemiconductor memory comprises: an under layer comprising a plurality ofmaterial layers-having different crystal structures; a first magneticlayer formed over the under layer and having a variable magnetizationdirection; a tunnel barrier layer formed over the first magnetic layer;and a second magnetic layer formed over the tunnel barrier layer andhaving a pinned magnetization direction, wherein the under layercomprises a first material layer that includes an Face Centered Cubic(FCC) crystal structure, a second material layer that includes a NaClcrystal structure, and a third material layer that includes a wurtzitecrystal structure.
 2. The electronic device of claim 1, wherein theunder layer comprises a first material layer; a second material layer;and a third material layer which have different crystal structures fromeach other, wherein the third material layer comprises a dusting layer.3. An electronic device comprising a semiconductor memory, wherein thesemiconductor memory comprises: an under layer comprising a plurality ofmaterial layers having different crystal structures; a first magneticlayer formed over the under layer and having a variable magnetizationdirection; a tunnel barrier layer formed over the first magnetic layer;and a second magnetic layer formed over the tunnel barrier layer andhaving a pinned magnetization direction, wherein the under layercomprises a first material layer; a second material layer; and a thirdmaterial layer which have different crystal structures from each other,wherein the third material layer comprises a dusting layer, wherein theunder layer has a multi-stack structure in which the first materiallayer, the second material layer and the third material layer aresequentially stacked.
 4. The electronic device of claim 3, wherein thethird material layer is formed to have a thickness in a range from about0.5 Å to about 2Å.
 5. The electronic device of claim 2, wherein theunder layer has a multi-stack structure in which the first materiallayer, the third material layer and the second material layer aresequentially stacked.
 6. The electronic device of claim 5, wherein thethird material layer is formed to have a thickness in a range from about0.5 Å to about 2Å.
 7. (canceled)
 8. The electronic device of claim 1,wherein the first material layer comprises a metal nitride having an FCCcrystal structure.
 9. The electronic device of claim 1, wherein thefirst material layer comprises zirconium nitride (ZrN), hafnium nitride(HfN), titanium nitride (TiN) or molybdenum nitride (MoN).
 10. Theelectronic device of claim 1, wherein the second material layercomprises a metal oxide having a NaCl crystal structure.
 11. Theelectronic device of claim 1, wherein the second material layercomprises magnesium oxide (MgO) or zirconium oxide (ZrO).
 12. Theelectronic device of claim 1, wherein the third material layer comprisesaluminum nitride (AlN), silver iodide (AgI), zinc oxide (ZnO), cadmiumsulfate (CdS), cadmium selenide (CdSe), silicon carbide (SiC), galiumnitride (GaN) or boron nitride (BN).
 13. The electronic device accordingto claim 1, further comprising a microprocessor which includes: acontrol unit configured to receive a signal including a command from anoutside of the microprocessor, and performs extracting, decoding of thecommand, or controlling input or output of a signal of themicroprocessor; an operation unit configured to perform an operationbased on a result that the control unit decodes the command; and amemory unit configured to store data for performing the operation, datacorresponding to a result of performing the operation, or an address ofdata for which the operation is performed, wherein the semiconductormemory is part of the memory unit in the microprocessor.
 14. Theelectronic device according to claim 1, further comprising a processorwhich includes: a core unit configured to perform, based on a commandinputted from an outside of the processor, an operation corresponding tothe command, by using data; a cache memory unit configured to store datafor performing the operation, data corresponding to a result ofperforming the operation, or an address of data for which the operationis performed; and a bus interface connected between the core unit andthe cache memory unit, and configured to transmit data between the coreunit and the cache memory unit, wherein the semiconductor memory is partof the cache memory unit in the processor.
 15. The electronic deviceaccording to claim 1, further comprising a processing system whichincludes: a processor configured to decode a command received by theprocessor and control an operation for information based on a result ofdecoding the command; an auxiliary memory device configured to store aprogram for decoding the command and the information; a main memorydevice configured to call and store the program and the information fromthe auxiliary memory device such that the processor can perform theoperation using the program and the information when executing theprogram; and an interface device configured to perform communicationbetween at least one of the processor, the auxiliary memory device andthe main memory device and the outside, wherein the semiconductor memoryis part of the auxiliary memory device or the main memory device in theprocessing system.
 16. The electronic device according to claim 1,further comprising a data storage system which includes: a storagedevice configured to store data and conserve stored data regardless ofpower supply; a controller configured to control input and output ofdata to and from the storage device according to a command inputted forman outside; a temporary storage device configured to temporarily storedata exchanged between the storage device and the outside; and aninterface configured to perform communication between at least one ofthe storage device, the controller and the temporary storage device andthe outside, wherein the semiconductor memory is part of the storagedevice or the temporary storage device in the data storage system. 17.The electronic device according to claim 1, further comprising a memorysystem which includes: a memory configured to store data and conservestored data regardless of power supply; a memory controller configuredto control input and output of data to and from the memory according toa command inputted form an outside; a buffer memory configured to bufferdata exchanged between the memory and the outside; and an interfaceconfigured to perform communication between at least one of the memory,the memory controller and the buffer memory and the outside, wherein thesemiconductor memory is part of the memory or the buffer memory in thememory system.